diff --git a/container/container.go b/container/container.go index 3ced7ff04..1866bff40 100644 --- a/container/container.go +++ b/container/container.go @@ -133,6 +133,8 @@ func (c *container) getResolver(typ reflect.Type) (resolver, error) { return c.resolvers[typ], nil } +var stringType = reflect.TypeOf("") + func (c *container) addNode(provider *ProviderDescriptor, key *moduleKey) (interface{}, error) { providerGraphNode, err := c.locationGraphNode(provider.Location, key) if err != nil { @@ -140,12 +142,17 @@ func (c *container) addNode(provider *ProviderDescriptor, key *moduleKey) (inter } hasModuleKeyParam := false + hasOwnModuleKeyParam := false for _, in := range provider.Inputs { typ := in.Type if typ == moduleKeyType { hasModuleKeyParam = true } + if typ == ownModuleKeyType { + hasOwnModuleKeyParam = true + } + if isAutoGroupType(typ) { return nil, fmt.Errorf("auto-group type %v can't be used as an input parameter", typ) } else if isOnePerModuleType(typ) { @@ -170,7 +177,7 @@ func (c *container) addNode(provider *ProviderDescriptor, key *moduleKey) (inter c.addGraphEdge(typeGraphNode, providerGraphNode) } - if key != nil || !hasModuleKeyParam { + if !hasModuleKeyParam { c.logf("Registering %s", provider.Location.String()) c.indentLogger() defer c.dedentLogger() @@ -227,6 +234,11 @@ func (c *container) addNode(provider *ProviderDescriptor, key *moduleKey) (inter return sp, nil } else { + if hasOwnModuleKeyParam { + return nil, errors.Errorf("%T and %T must not be declared as dependencies on the same provided", + ModuleKey{}, OwnModuleKey{}) + } + c.logf("Registering module-scoped provider: %s", provider.Location.String()) c.indentLogger() defer c.dedentLogger() @@ -314,6 +326,15 @@ func (c *container) resolve(in ProviderInput, moduleKey *moduleKey, caller Locat return reflect.ValueOf(ModuleKey{moduleKey}), nil } + if in.Type == ownModuleKeyType { + if moduleKey == nil { + return reflect.Value{}, errors.Errorf("trying to resolve %T for %s but not inside of any module's scope", moduleKey, caller) + } + c.logf("Providing OwnModuleKey %s", moduleKey.name) + markGraphNodeAsUsed(typeGraphNode) + return reflect.ValueOf(OwnModuleKey{moduleKey}), nil + } + vr, err := c.getResolver(in.Type) if err != nil { return reflect.Value{}, err diff --git a/container/container_test.go b/container/container_test.go index 3eb7e367b..ce8494c52 100644 --- a/container/container_test.go +++ b/container/container_test.go @@ -15,14 +15,13 @@ type KVStoreKey struct { name string } -type ModuleKey string - type MsgClientA struct { - key ModuleKey + key string } type KeeperA struct { - key KVStoreKey + key KVStoreKey + name string } type KeeperB struct { @@ -46,18 +45,14 @@ func ProvideKVStoreKey(moduleKey container.ModuleKey) KVStoreKey { return KVStoreKey{name: moduleKey.Name()} } -func ProvideModuleKey(moduleKey container.ModuleKey) (ModuleKey, error) { - return ModuleKey(moduleKey.Name()), nil -} - -func ProvideMsgClientA(_ container.ModuleKey, key ModuleKey) MsgClientA { - return MsgClientA{key} +func ProvideMsgClientA(key container.ModuleKey) MsgClientA { + return MsgClientA{key.Name()} } type ModuleA struct{} -func (ModuleA) Provide(key KVStoreKey) (KeeperA, Handler, Command) { - return KeeperA{key}, Handler{}, Command{} +func (ModuleA) Provide(key KVStoreKey, moduleKey container.OwnModuleKey) (KeeperA, Handler, Command) { + return KeeperA{key: key, name: container.ModuleKey(moduleKey).Name()}, Handler{}, Command{} } type ModuleB struct{} @@ -76,7 +71,7 @@ type BProvides struct { Commands []Command } -func (ModuleB) Provide(dependencies BDependencies, _ container.ModuleKey) (BProvides, Handler, error) { +func (ModuleB) Provide(dependencies BDependencies) (BProvides, Handler, error) { return BProvides{ KeeperB: KeeperB{ key: dependencies.Key, @@ -95,7 +90,8 @@ func TestScenario(t *testing.T) { require.Equal(t, Handler{}, handlers["b"]) require.Len(t, commands, 3) require.Equal(t, KeeperA{ - key: KVStoreKey{name: "a"}, + key: KVStoreKey{name: "a"}, + name: "a", }, a) require.Equal(t, KeeperB{ key: KVStoreKey{name: "b"}, @@ -104,11 +100,8 @@ func TestScenario(t *testing.T) { }, }, b) }, - container.Provide( - ProvideKVStoreKey, - ProvideModuleKey, - ProvideMsgClientA, - ), + container.Provide(ProvideMsgClientA), + container.ProvideInModule("runtime", ProvideKVStoreKey), container.ProvideInModule("a", wrapMethod0(ModuleA{})), container.ProvideInModule("b", wrapMethod0(ModuleB{})), )) diff --git a/container/module_key.go b/container/module_key.go index 79777dc09..1b57983bf 100644 --- a/container/module_key.go +++ b/container/module_key.go @@ -6,14 +6,17 @@ import ( // ModuleKey is a special type used to scope a provider to a "module". // -// Special module-scoped providers can be used with Provide by declaring a -// provider with an input parameter of type ModuleKey. These providers -// may construct a unique value of a dependency for each module and will -// be called at most once per module. +// Special module-scoped providers can be used with Provide and ProvideInModule +// by declaring a provider with an input parameter of type ModuleKey. These +// providers may construct a unique value of a dependency for each module and +// will be called at most once per module. // -// Providers passed to ProvideInModule can also declare an input parameter -// of type ModuleKey to retrieve their module key but these providers will be -// called at most once. +// When being used with ProvideInModule, the provider will not receive its +// own ModuleKey but rather the key of the module requesting the dependency +// so that modules can provide module-scoped dependencies to other modules. +// +// In order for a module to retrieve their own module key they can define +// a provider which requires the OwnModuleKey type and DOES NOT require ModuleKey. type ModuleKey struct { *moduleKey } @@ -28,4 +31,8 @@ func (k ModuleKey) Name() string { var moduleKeyType = reflect.TypeOf(ModuleKey{}) -var stringType = reflect.TypeOf("") +// OwnModuleKey is a type which can be used in a module to retrieve its own +// ModuleKey. It MUST NOT be used together with a ModuleKey dependency. +type OwnModuleKey ModuleKey + +var ownModuleKeyType = reflect.TypeOf((*OwnModuleKey)(nil)).Elem()